The conventional pedestrian traffic signal system consists of a walk signal head, a stop signal head, an audio signal generator for the blind and a remaining time counter of each signal change separately. Thus, the cost of system was comparatively higher due to separate fabrication, installation, and maintenance, creating an obstacle to speedy popularization.
To overcome the above problems, a single pedestrian traffic signal system was introduced, however, the single system is displaying the remaining time in two digit numbers and it makes difficulties for the disabled person in weak sight and the illiterate as well as difficulties for recognizing from a relatively long distance.
Moreover, the conventional audible signal generator for the blind at the crossroad was designed to generate an electronic sound signal only, so that the blind could not distinguish the remaining time of the walk signal change, causing inconvenience to the blind pedestrians.
Moreover, the conventional pedestrian traffic signal system could not diagnose a malfunction of the system by itself, nor give warning remotely of the malfunction to the management facilities, causing neglect of the malfunction for a long time.
Moreover, the conventional pedestrian traffic signal system could not detect the existence or the nonexistence of pedestrians at crossroad sides of two-way street, causing unnecessary interruption of traffic flow by changing signal even if there is no pedestrian.
Moreover, the conventional traffic signal system for drivers cannot display the remaining time of each signal change at the cross road and it caused the traffic accidents since drivers could not predict when the signal will change and hurry up to cross.